fix: complete skip-compress protocol handling

tests/integration/test_features.py

@@ -80,6 +80,35 @@ class TestSkipCompress:
         assert not missing, f"Missing: {missing}"
         assert not mismatches, f"Mismatch: {mismatches}"
 
+    def test_skip_compress_incremental_full_fallback(self, shared_server):
+        clean_dir(DEST_DIR)
+        path = os.path.join(SOURCE_DIR, "incremental-skip.TXT")
+        with open(path, "wb") as f:
+            f.write(b"original skipped content\n")
+        flags = ["-c", "-M", "--skip-compress=.txt"]
+        result, _ = run_client(SOURCE_DIR, DEST_DIR, flags=flags, port=shared_server.port)
+        assert result.returncode == 0, f"Initial sync failed: {(result.stderr or result.stdout)[:200]}"
+        with open(path, "wb") as f:
+            f.write(b"updated skipped content\n")
+        result, _ = run_client(
+            SOURCE_DIR, DEST_DIR,
+            flags=flags + ["--incremental"],
+            port=shared_server.port,
+        )
+        assert result.returncode == 0, f"Incremental sync failed: {(result.stderr or result.stdout)[:200]}"
+        received = get_dest_received_dir(DEST_DIR, SOURCE_DIR)
+        with open(os.path.join(received, "incremental-skip.TXT"), "rb") as f:
+            assert f.read() == b"updated skipped content\n"
+
+    def test_skip_compress_rejects_chunk_serialization(self, shared_server):
+        result, _ = run_client(
+            SOURCE_DIR, DEST_DIR,
+            flags=["-c", "-s", "--skip-compress=.txt"],
+            port=shared_server.port,
+        )
+        assert result.returncode != 0
+        assert "cannot be combined" in (result.stderr or result.stdout)
+
 
 class TestExclude:
     def test_exclude_single(self, shared_server):

tests/test_client_cli.c

@@ -36,6 +36,9 @@ static void test_validate_config_incompatible_options() {
   cfg->use_incremental = true;
   cfg->use_chunk_serialization = true;
   EXPECT_FALSE(validate_config(cfg));
+  cfg->use_incremental = false;
+  cfg->skip_compress_set = true;
+  EXPECT_FALSE(validate_config(cfg));
   config_delete(cfg);
 }
 

tests/test_config.c

@@ -121,11 +121,15 @@ static void test_config_send_receive() {
   send_cfg->receive_root_directory = str_dup("/send/dst");
   send_cfg->save_to_disk = true;
   send_cfg->use_multithreading = true;
-  send_cfg->use_chunk_serialization = true;
+  send_cfg->use_chunk_serialization = false;
   send_cfg->use_compression = true;
   send_cfg->use_metadata = true;
   send_cfg->compression_level = 5;
   send_cfg->chunk_size = 1024;
+  send_cfg->skip_compress_set = true;
+  send_cfg->skip_compress_count = 1;
+  send_cfg->skip_compress_suffixes = calloc(1, sizeof(char*));
+  send_cfg->skip_compress_suffixes[0] = str_dup(".zip");
 
   /* Use socketpair for bidirectional communication */
   int p[2];
@@ -154,12 +158,15 @@ static void test_config_send_receive() {
         ok = false;
       if (!recv_cfg->use_multithreading)
         ok = false;
-      if (!recv_cfg->use_chunk_serialization)
+      if (recv_cfg->use_chunk_serialization)
         ok = false;
       if (recv_cfg->compression_level != 5)
         ok = false;
       if (recv_cfg->chunk_size != 1024)
         ok = false;
+      if (!recv_cfg->skip_compress_set || recv_cfg->skip_compress_count != 1 ||
+          strcmp(recv_cfg->skip_compress_suffixes[0], ".zip") != 0)
+        ok = false;
     }
     config_delete(recv_cfg);
     close(p[0]);